The present invention relates to an improved yarn winding apparatus of the revolving type, which ensures unfailing winding of yarns which are fed continuously at high speed. The yarns are taken up on bobbins and the winder facilitates shifting of yarn from a full bobbin to an empty bobbin.
In operation, yarns are fed continuously on bobbins as in the process of spinning or of drawing synthetic fibers. It is a problem to smoothly shift a yarn from a full bobbin to an empty one. If this operation is not properly performed large amounts of waste yarns are produced, and interruptions are encountered.
A typical yarn shifting operation might include two winders, installed side by side, so as to arrange the bobbins of the winders in a straight line. When the bobbin on one of the two winders becomes full, an operator manually shifts the yarn to an empty bobbin on the other winder. However, it is necessary to provide two winders for each spinning frame. Further, a larger space is needed to arrange the bobbins as above, and this makes the necessary equipment rather expensive.
In order to remedy such drawbacks as mentioned above, a different type of winder, the so-called "revolving" winder, has been suggested. A plurality of shafts is fitted into a rotatory body, and when a bobbin becomes full of yarn, the rotatory body is revolved so as to shift the yarn to a new empty bobbin on which it is to be wound. A spindle drive revolving winder, for example, as disclosed in Japanese Patent Publication No. 3488/1966, is, in particular, looked upon as promising for operations at higher speeds in the future.
In the above mentioned revolving winder, however, a motor is positioned at an end of the spindle which supports the bobbin, and the spindle is driven directly by the motor. The structure is such that the motor is fastened to the rotatory body; therefore the equipment is inevitably accompanied by shortcomings.
Namely, in order to drive the spindle at higher speed, it is necessary to use a corresponding larger motor. As the size of motor becomes larger, the whole equipment necessarily becomes larger. If, on the contrary, the winding equipment is designed in a smaller size, there is naturally a limitation on the speed of rotation of the spindle.
Further, when a motor is fastened to the rotatory body, there arises the necessity of providing a slip ring for the supply of electricity for driving it. Still further, with decrease in the diameter of the bobbin, so that it will have the desired geometry to take up a larger amount of yarn, it becomes more difficult to fix the motor in a chuck.
In effect, with the revolving type yarn winding apparatus wherein the spindle is driven directly by a motor, there are many practical limitations on its structural design.